Systems and Methods of Detection of Transmission Facilities

ABSTRACT

A method of detecting a transmitting device within an obstruction rich environment is disclosed. The method may involve detecting the transmitting device with a wireless transmission detection facility; communicating signal information relating to the detected transmitting device from the wireless transmission detection facility to a central unit; determining the location of the transmitting device; displaying information of the detection and location of the transmitting device through a user interface; and providing an action facility for causing actions related to the detected transmitting device.

CLAIM OF PRIORITY

This application claims the benefit of the earlier filing date, pursuantto 35 USC §120, as a Continuation of that patent application entitled“Systems and Methods for Detection of Transmission Facilities,” filed inthe United States Patent and Trademark Office on Jul. 27, 2009 andafforded Ser. No. 12/510,006, which claims the benefit as a continuationof that patent application entitled “Systems and Methods for Detectionof Transmission Facilities,” filed in the United States Patent andTrademark Office on Jul. 14, 2006 and afforded Ser. No. 11/457,786,which claims the benefit of the filing dates, pursuant to 35 USC 119, toU.S. Provisional App. No. 60/699,281 filed on Jul. 14, 2005 and U.S.Provisional App. No. 60/739,877 filed on Nov. 23, 2005. This applicationis further claims the benefit of the earlier filing date, pursuant to 35USC 119, to that provisional patent application, entitled “System andMethod of Detection of Transmission Facilities”, “filed in the UnitedStates Patent and Trademark Office on Jun. 19, 2010 and afforded Ser.No. 61/356,556. The entire content of these applications beingincorporated by reference, herein.

BACKGROUND

1. Field of the Invention

This invention relates to location of transmission facilities and moreparticularly to the location of transmission facilities, such ascellular phones, in correctional institutions and controlling their use.

2. Background

There are many facilities, such as government buildings, and inparticular correctional facilities, such as prisons, that do not permitcellular phone usage on the premises or even possession of cell phonesin the premises. Finding and preventing usage of cell phones and othertransmission facilities is difficult, and a need exists for improvedmethods of locating such devices, as well as a need for detecting suchdevices upon ingress to a facility.

SUMMARY

Provided herein are methods and systems for locating transmissionfacilities such as cell phones, mobile phones, satellite phones, radios,transmitters, PDAs, beepers, pagers, walkie-talkies, email devices,instant messenger devices, voice over IP devices, and other types ofwireless communication or transmission facilities, and when necessarycontrolling such transmission facilities.

Embodiments relate to locating and managing the use and presence ofwireless communication facilities. Embodiments relate to detecting suchdevices when they transmit a signal. Other embodiments relate todetecting non-active transmission facilities.

In certain embodiments the methods and systems disclosed herein includemethods and systems for detecting a transmitting device within anobstruction rich environment. The methods and systems may includedetecting the transmitting device with a wireless transmission detectionfacility; communicating signal information relating to the detectedtransmitting device from the wireless transmission detection facility toa central unit; determining the location of the transmitting device;displaying information of the detection and location of the transmittingdevice through a user interface; and providing an action facility forcausing actions related to the detected transmitting device. Inembodiments, the wireless transmission detection facility is an antenna.In embodiments, the antenna is a dual dipole embedded antenna. Inembodiments, the dual dipole embedded antenna is tuned to receive cellphone transmissions. In embodiments the dual dipole embedded antenna istuned to receive a frequency band of approximately 700 to 950 MHz. Inembodiments the dual dipole embedded antenna is tuned to receive afrequency band of approximately 1.7 to 2.0 GHz. In embodiments the dualdipole antenna is tuned to receive signals in frequency bands ofapproximately 700 to 950 MHz and 1.7 to 2.0 GHz. In embodiments theobstruction rich environment is a correctional facility. In embodimentsthe obstruction rich environment is a mall. In embodiments communicatingthe information relating to the detected transmitting device from thewireless transmission detection facility to a central unit involveswireless communications. In embodiments the wireless communications are802.11 communications. In embodiments determining the location of thetransmitting device is accomplished through transmission triangulation.In embodiments location of the transmitting device is accomplishedthrough a known location of a single antenna.

BRIEF DESCRIPTION OF FIGURES

The systems and methods described herein may be understood by referenceto the following figures:

FIG. 1 shows a transmission detection, identification, and reportingsystem.

FIG. 2 illustrates a system for detecting a transmission facility

FIG. 3 illustrates antenna configurations.

FIG. 4 illustrates a system for detecting a transmission facility in acell environment.

FIG. 5 shows a system for detecting a transmission facility in a cellenvironment.

FIG. 6 illustrates a block diagram relating to actions taken whendetecting transmission facilities.

FIG. 7 shows a transmission facility detection system wherein an antennaarray is used to calculate location.

FIG. 8 shows a transmission facility detection system wherein a signalsource is differentiated between two adjacent rooms.

FIG. 9 illustrates a transmission facility detection system whereinmultiple antennas are used to identify the location of a signal sourceafter an omni-directional antenna has detected its presence.

FIG. 10 shows a schematic diagram of a system for detecting signals of atransmission facility.

FIG. 11 shows a schematic diagram of an alternate embodiment of a systemfor detecting a signal of a transmission facility.

FIG. 12 shows a schematic diagram of a main circuit board within asystem for detecting transmission facilities.

FIG. 13 shows a schematic diagram of a sub-station in a system fordetecting transmission facilities.

FIG. 14 illustrates a null detection facility.

DETAILED DESCRIPTION OF FIGURES

Detection of a transmission facility, such as a mobile phone orhand-held radio transmitter, or other transmission facility as describedherein, within an obstruction rich environment, such as a facility withmany physical barriers to electronic transmission, is difficult toachieve. Referring to FIG. 1, the transmission detection,identification, and reporting system 100 described herein provides amethod of detecting a transmission facility 202, such as depicted inFIG. 2, within an environment rich in obstructions 102. One embodimentof the transmission detection, identification, and reporting system 100may involve the detection of a mobile phone within a heavily walled andmetal-barred government facility such as a correctional facility. Inthis embodiment, the system may utilize an array of antennas 104selectively placed within the facility, collection substations 108 forlocalized collection of detected signals, a central unit 110 for theprocessing of incoming signals from the facility, a display 112 forshowing the location of the detected transmission facility 202, and anaction facility 114 for implementing standard procedures in the event ofa detection. In this embodiment, the communications between the antennas104 and the substations 108, and between the substations 108 and thecentral unit 110, may be wireless to make installation and maintenanceof the system within the facility, cost and time effective. Selectiveplacement of the antennas 104, combined with algorithms and methods fordetermining location of the transmission facility 202, may allow asubstantially improved means for locating transmission facilities 202,such as mobile phones, in an otherwise heavily shielded environment.

In embodiments the antenna 104 may be a multi-dipole embedded antenna.Two examples of dual dipole embedded antennas are provided in FIG. 3 asa first dual-dipole embedded antenna 302 and a second dual dipoleembedded antenna 304. In embodiments the antenna may be adapted toreceive one, two, three, four, or more bandwidths. In embodiments theantenna 104 may be a dipole antenna 104, a Yagi-Uda antenna 104, a loopantenna 104, a quad antenna 104, a micro-strip antenna 104, a quadantenna 104, a helical antenna 104, a phase array antenna 104, a patchantenna or the like.

In embodiments, the transmission facility 202 may be a mobile phone,such as a flip phone, a slide phone, a cellular phone, a handset, asatellite phone, a 3G phone, a wireless phone, a cordless phone or thelike. In embodiments, the transmission facility 202 may be a radio, suchas a walkie-talkie, a mobile radio, a short-wave radio, or the like. Inembodiments, the transmission facility 202 may be a wirelesscommunication device like a laptop computer, a wireless modem, 802transceivers technology and the like.

In embodiments, the transmission band from the transmission may bewithin the radio or other electromagnetic frequency spectrum, such asextremely low frequency (ELF), super low frequency (SLF), ultra lowfrequency (ULF), very low frequency (VLF), low frequency (LF), mediumfrequency (MF), high frequency (HF), very high frequency (VHF), ultrahigh frequency (UHF), super high frequency (SHF), extremely highfrequency (EHF), microwave, a frequency suitable for 802.11x wirelesscommunications, ultra wide band (UWB), Bluetooth, or the like.

In embodiments, the obstruction 102 rich environment may be a building,such as a corrections facility, a school, a government facility, astore, a mall, a residence, a hotel, a motel, or the like. Inembodiments, the obstruction 102 rich environment may be a largeconfined space, such as a courtyard, a food court, a recess area, ahallway, greenhouse, recreation room, gymnasium, auditorium, kitchen,cafeteria, craft area, work area, library, prison yard, or the like. Inembodiments, the obstruction 102 may be a transmission, devicetransmission obstruction 102, such as cinderblock, cement, rebar, wirecage, metal, metal coated surface, or the like. In embodiments, theobstruction 102 may be other construction materials, such as wood,glass, rug, flooring materials, roofing materials, and the like.

In embodiments, the transmitting signal information from the antenna 104module to the central unit 110 may be through a communicationsconnection, such as an IEEE 802.15.4 wireless network, IEEE 802.11Wi-Fi, Bluetooth, Ethernet, or the and the like. In embodiments, thecommunications connection may utilize CAT-5, RJ-45, RS-232 connections,and the like. In embodiments the communications connection may utilizean optical connection, such as a wireless infrared link, an opticalfiber, and the like.

In embodiments, the transmitting signal information from the antenna 104module to the central unit 110 may contain data, such as CDMA, CDPD,GSM, TDMA, and the like, and may be used to discriminate which servicesignal is being used, such as Verizon, Cingular, T-Mobile, Sprint, andthe like. The detection of the cell phones may be resolved down to cellphone manufacturer and cell phone provider.

In embodiments, the transmitting signal information to the central unit110 may be made through an intermediate connection, such as a substation108, router, switch, hub, bridge, multiplexer, modem, network card,network interface, processing unit, preprocessor, computer, repeater,antenna 104, and the like.

In embodiments, the central unit 110 may have in part a computer, acomputer system, a network of computers, a state machine, a sequencer, amicroprocessor, a digital signal processor, an audio processor, apreprocessor, a microprocessor, and the like.

In embodiments, the central unit 110 may process information, such aslocation information, such as the location of people, inmates,corrections personnel, visitors, all personnel within the facility,equipment, resources, weapons, products, incoming goods, outgoing goods,and the like. In embodiments, the information may be type of signal,such as mobile phone standard protocols such as CDMA, CDPA, GSM, TDMA,and the like. In embodiments, the information may be an eventnotification, such as personnel under duress, an emergency medicalcondition, a call for assistance, a fire, a call for police, a theft,and the like. In embodiments, the processed information may allow forthe tracking of the person or object in possession of the transmissionfacility 202, such as a mobile phone, a radio, a weapon, a product, aresource, and the like. In embodiments, the processed information mayallow for the discrimination and/or association between people orobjects, such as determining the ownership of the transmission facility202, the assignment of the source of transmission, current location of atransmission facility 202 compared to its predicted location, and thelike. In embodiments, the processed information may also have time codesand unique identifiers assigned.

In embodiments, the central unit 110 may have a display 112, such as acathode ray tube (CRT), liquid crystal display 112 (LCD), electronicpaper, 3D display 112, head-mounted display 112, projector, segmenteddisplay 112, computer display 112, graphic output display 112, and thelike. In embodiments, the central unit 110 may have an action facility114, comprising a user interface for causing actions relating to thedetected transmission facility 202, such as closing a door, sealing aroom, deploying and action signal, initiating an alarm, and the like.

In embodiments the functions of a central unit 110 as described hereinmay be replaced by an alternate configuration, such as a configurationof multiple computers, such as a group of servers, processors, or thelike, operating in parallel. In embodiments the methods and systemsdescribed herein may involve locating computing capabilities inalternative network configurations, such as in a mesh network or apeer-to-peer network.

In embodiments, the location of a transmission facility 202 may bedetermined by various radiolocation or signal measurement techniques,including measuring phase, amplitude, time, or a combination of these;or by identifying and locating an area associated with an antenna 104with the highest signal strength. In embodiments, the location of atransmission facility 202 may be determined when the transmissionfacility 202 is powered off though detection of a null in the band passof a transmitted frequency sweep due to the presence of a mobile phoneantenna.

In embodiments, a method of detecting a transmission facility 202 (e.g.cell phone) when the transmission facility 202 is not powered mayrequire a transmitting device and a receiving device that can recognizethe signature of an antenna 104 associated with the transmissionfacility 202. By transmitting a known frequency and receiving thedisturbance pattern produced by having a particular antenna 104 designin the transmission path, the pattern or ‘signature’ of that antenna 104can be characterized. In embodiments, this characterization may beevaluated with a microprocessor 1402 with results output to a display112. A database of these signatures can be placed into the device, andas the transmitter sweeps across the various cell frequencies, a patternreceived can be matched against the database patterns to determine thepresence of transmission facilities 202. In embodiments, any class ofantenna (e.g. WI-FI, Blackberry, Walkie-Talkie, etc.) can be classifiedand identified.

In embodiments, the range of a hand held device that can detect aninactive transmission facility is approximately 10 feet. In embodiments,greater distances could be attained for stationary units by increasingthe power.

Radiolocation, also referred to as radio-determination, as used hereinencompasses any process of finding the location of a transmitter bymeans of the propagation properties of waves. The angle, at which asignal is received, as well as the time it takes to propagate, may bothcontribute to the determination of the location of the transmissionfacility 202. There are a variety of methods that may be employed in thedetermination of the location of a transmission facility 202. Methodsinclude (i) a cell-sector system that collects information pertaining tocell and sector ID's, (ii) the assisted-global positioning satellite(GPS) technology utilizing a GPS chipset in a mobile communicationfacility, (iii) standard GPS technology, (iv) enhanced-observed timedifference technology utilizing software residing on a server that usessignal transmission of time differences received by geographicallydispersed radio receivers to pinpoint a user's location, (v) timedifference of arrival, (vi) time of arrival, (vii) angle of arrival,(viii) triangulation of cellular signals, (ix) location based onproximity to known locations (including locations of otherradio-transmitters), (x) map-based location, or any combination of anyof the foregoing, as well as other location facilities known to those ofskill in the art.

Obstructions 102 to radio wave propagation may greatly reduce theeffectiveness of many of the conventional radiolocation methods due toobstruction of the line-of-sight between the transmission facilities 202and the receiving antennas 104. However, by employing a large array ofantennas 104, positioned so as to maintain line-of-sight betweenpossible transmission facility 202 locations and the receiving antennas104, several of these methods may be effectively used in the location ofthe transmission facility 202. These methods include time difference ofarrival, time of arrival, and angle of arrival, amplitude comparison,and the like. The time difference of arrival method determines thedifference in the time, or the difference in phase, of the sameradio-transmitting signal arriving at different receiving antennas 104.Together with the known propagation speed of the radio wave, allows thedetermination of the location of the transmission facility 202. The timeof arrival method determines the absolute time of reception of thesignal at different receiving antennas 104, and again, along with theknown propagation speed of the radio wave, allows the determination ofthe location of the transmission facility 202. The angle of arrivalmethod utilizes direction of transmission to different antennas 104 todetermine the location of the transmission facility. Amplitudecomparison method compares the strength of the signal detected at eachantenna to determine the location of a transmission facility 202. Forexample, two antennas 104 located in the same room would detectdifferent signal amplitudes for the same transmission facility 202output, thereby providing a means of determining which antenna 104 thetransmission facility 202 is closer to. Increasing the number ofantennas 104 therefore increases the resolution with which the locationof the transmission facility 202 may be determined. All of thesemethods, and combinations of these methods, may employ mathematicalprocesses such as triangulation, trilateration, multilateration, orlike, in determining the location of the transmission facility.

Triangulation is the process of finding coordinates and distance to apoint by calculating the length of one side of a triangle, givenmeasurements of angles and/or sides of the triangle formed by thatpoint, such as the target transmission facility 202, and two other knownreference points, such as the receiving antennas 104. The calculation ofthe location of the transmission facility 202 may then be performedutilizing the law of sines from trigonometry. Tri-lateration is a methodsimilar to triangulation, but unlike triangulation, which uses anglemeasurements, together with at least one known distance, to calculatethe subject's location, tri-lateration uses the known locations of twoor more reference points and the measured distance to the subject, suchas the transmission facility 202, and each reference point, such as thereceiving antennas 104. Multi-lateration, or hyperbolic positioning, issimilar to tri-lateration, but multi-lateration uses measurements oftime difference of arrival, rather than time of arrival, to estimatelocation using the intersection of hyperboloids.

While several radiolocation and triangulation techniques have beendescribed in connection with locating the transmitting device, it shouldbe understood that one skilled in the art would appreciate that thereare other location methodologies and such location methodologies areencompassed by the present invention. For example, in embodiments, thelocation of a single antenna may be known and the single antenna maydetect a transmitting device. The location of the transmitting devicemay be estimated through its known proximity to the single antennalocation. This may provide adequate location resolution for certainapplications of the technology. Similarly, two or more antennas may beused and each of the antenna locations may be known. When each of theantennas receives a transmission, the corresponding signal strengths maybe compared. The one with the highest signal strength may be determinedas the one closest to the transmitting device so the correspondingantenna location may provide enough location resolution for certainapplications.

In an embodiment of the transmission detection, identification, andreporting system 100, a corrections facility, with its substantial andinherent obstruction 102 rich environment, presents an ideal example ofhow the transmission detection, identification, and reporting system 100may significantly increase the detection of transmission facilities 202such as mobile phones, a significant challenge to authorities of thecorrection facilities. In this embodiment, the system maybe placedthroughout the corrections facility for the purpose of alerting thecorrections staff that cell phone activity is taking place, the locationof the activity and the type, i.e., Nextel, T-Mobile, Verizon, and thelike. The following technology may also allow for a standalone detectionunit 408 or set of detection units 408 to detect cell phones in schools,buildings and other environments in which the facility's or area'sprovider does not wish the use of cell phones and is interested in thedetection of cell phone use.

In an embodiment, the system may include an integrated antenna 104 andRF detector (together referred to as a detector unit 408), a substation108, whose purpose may be to communicate with each detector unit 408within its sector, and report activity to the central unit 110 whichreports confirmed activity, type of cell phone, and location to thedisplay 112 of the central unit 110. These detection units 408 may beused individually or in conjunction with each other and may triangulatedetection within a specific area. The outside yard areas may bemonitored by detection units 408, which may cover large areas, such as25×25 foot sectors or 5×5 foot sectors, to localize the detection of acell phone and track its position from one sector to any adjoiningsector. That is, as the person moves with a phone, the changing positionof that phone may be reported. If the phone moves inside the facility,tracking may continue as interior detection units 408 detect the phone.

In an embodiment, within these basic groups of detection units 408 maybe various detection unit 408 types. Some detection unit 408s may bedesigned to be hard wired via RJ-45 connectors and CAT 5e cable, otherdetection units 408 may use 802.11b (WI-FI) wireless communicationsbetween detection units 408, and there may also be an Infra Red (IR) setof detection units 408 which utilize optical communications techniques.Each communications type may have a specific purpose within thecorrections facility or other type of building and/or areas. Hard-wiredunits may be used when it is not possible to use either an optical unitor a WI-FL unit. Used when there are walls embedded with metal or wherethe distance and the obstructions 102 may preclude a wireless technique.WI-FL detection units 408 be used when it is effective to communicate inan area where there are obstructions 102 such as cement walls or cementwith embedded rebar walls, facades, and the like. Optical detectionunits 408 may be used in areas where clear, line-of-site communicationsmay be possible. Optical detection units 408 may operate over relativelylong distances, such as 3,000 feet, while WI-FI detection units 408 maybe limited to shorter distances, such as 250 feet.

In an embodiment, there may also be a hand-held detection units 408 tobe used once a cell phone has been detected, and the correctionsofficer(s) or monitor are attempting to pinpoint the location. Thisdetection unit 408 may be similar to the integrated antenna/detectorunit of the main system. This detector unit 408 may output an audiblealarm whose pitch changes as the signal becomes stronger or weaker.

In an embodiment, a second type of hand-held detector unit 408 may beused to detect a cell phone when it is either off or in a standbycondition, also referred to as null detecting. Null detection may beused at an ingress or egress of a building or area as a way of detectinga communication device or device with an antenna. This technique may beused in areas where it is unpractical, unwanted or unwarranted to havex-ray machines or more intrusive detection systems. A null detectionsystem may also be deployed in a handheld device so an inspector canmove through an area attempting to detect a communication device. Inembodiments, the null detection system may detect the presence of atransmission facility even when the transmission facility is nottransmitting a signal. In embodiments, a hand held or mounted nulldetection device may be used in a correctional institution or othergovernment facility. In embodiments, null detection may utilize atransmission-detection source, independent of the transmission sourcebeing detected, which is capable of sweeping across the frequencyspectrum of interest and receiving its returning signal. Thetransmission source sweeps the spectrum of interest, searching fordistortions in the returned field. Distortions in the spectrum may bedue to the presence of an antenna of a transmission facility 202.Matching the distortion, also referred to as a null in the band pass, tocharacteristics of known antennas used with mobile phones may allow thedetection and/or identification of the transmission facility 202. Theunit may output an audible “beep” if it detects a null, allowing theofficers to focus in on the location of the cell phone. The range of thehand-held detection units 408 may be, for example, 15 to 20 feet. Thiswill allow cell phones that are in the immediate vicinity to be quicklydetected. The null detection may be applicable for egress detection.

In an embodiment, a survey may be performed to determine optimalplacement and the type and number of detection units 408 required. Thiswill insure the minimum number of required detection units 408 toperform optimal detection. The team may provide a report detailing thelayout determined to be optimized for the facility and may review thisreport with the facilities staff so that any required modifications tothe plan may be incorporated before installation is begun.

In an embodiment, the initial coverage of a facility may be in the cellblocks 402 and/or pod areas. The same may be true for linear facilities.The survey may cover the entire facility, including open areas, such ascourtyards, where required. But the most likely place for the initialinstall may be in the prison cellblocks 402, since that is where thehighest probability of detection may take place.

In an embodiment, the cell block units may be mounted inside each chase404 (a column positioned between cells in a cell block that includesvarious utility facilities, such as for plumbing and electricity), asshown in FIG. 4, and may communicate to a substation 108 located at oneend of the block. This detection unit 408 may communicate itsinformation to the central unit 110 so that tracking, confirmation, anddisplay may be accomplished. For linear facilities 500, detector units408 may be mounted along the walls 102, as shown in FIG. 5, opposite thecells 402 and perform their function similar to the detection units 408mounted within a chase 404.

In an embodiment, detector units 408 may be installed in open areas suchas gymnasiums, kitchens, cafeterias, craft and work areas and other openareas where a cell phone may be used. The difference in these locationsfrom the cell blocks 402 may include the method of detection andtracking. Since most facilities may only require the identification of acell phones presence within a room, and there could be many inmateswithin that room, the process may be to lock-down the room, or rooms, inthat area and use a hand held device and a physical search to pinpointthe phone location. A generalized block diagram is shown in FIG. 6. Forthose facilities that require resolving the location within a largeinterior room or area, the use of triangulation to resolve to a 10×10foot area may be used.

In an embodiment, facilities with the requirement to detect cell phones202 in outside yard areas, the use of triangulation to a 25×25 footspace or smaller foot space may be constructed. As a phone 202 is movedfrom area coverage 702 to area coverage 702, the system may track itsmovement. Each square foot sector may overlap an adjoining sector. Inthis way, as shown in FIG. 7, tracking may be continuous, without anygaps.

In an embodiment, it may also important to know whether a phone islocated on one side of an obstruction 102 or the other, such as doors,walls, and the like. If the wrong room is identified, it may make itmore difficult to locate a phone and its user. As shown in FIG. 8,detection of the correct room may depend upon the level of the signalreceived. Proper placement of the detector units 408 may insure that thephone may be identified in the correct location.

In an embodiment, when sectoring a large room such as a gymnasium, thenumber and placement of antennas 104 may be critical. In order to sectorlarge regions, such as a ten-by-ten ft section, within the room, theantenna 104 may need to be capable of narrowing their window to an areasmall enough to meet the requirement. In FIG. 9, there is anomni-directional antenna 104, which detects signal presence. Once asignal crosses a threshold, the direction finding antennas 104 may beturned on to determine the position of the signal. This may be reportedto the display 112 and tracked until it is either turned off or moves toanother room or hallway. Then, normal positional tracking may takeplace.

In an embodiment, the transmission detection, identification, andreporting system 100 may work in conjunction with a personal alarmsystem, This dual role system may allow for more cost effective use ofthe detection units 408 and provide for greater protection for thecorrectional officer. This detection system may utilize anindividualized frequency, with known frequency separation betweendetection units 408. The detection configuration of the detection units408 may provide complete coverage of the facility. Each unit may becontinually tracked throughout the facility. At all ingress or egresspoints the focus of the detection may ensure accurate location of allcorrectional personnel. With the combined systems more detection units408 may be need to ensure full coverage.

In an embodiment, the transmission detection, identification, andreporting system 100 may allow for cell phone (also referred to astransmission facility) owner discrimination. The system may provide forthe allowance of authorized cell phones within the prohibited area. Thesystem may detect and identify each cell phone or transmission facilityand compare the cell phone (transmission facility) identity to theallowed transmission facility user list. The system may record all phoneuse and may automatically alert the facility of all prohibited cellphone or transmission facility use. In addition, each cell phonedetection event may be identified with a unique identifier and timecode, to ensure proper identification. This maybe accomplished bydecoding the transmission facility. In an embodiment, the transmissiondetection, identification, and reporting system 100 the sensor unitdetermines the Time of Arrival (TOA), phone type, cell phone mode,amplitude, frequency, direction and phase of the transmission, thesensor unit also decodes the information within the transmission andextracts information to determine the cell phone identification.

The cell scan-1 detection system 1000, shown in FIG. 10, is anembodiment of a system for detecting signals of a transmission facility.Antenna 104 receives transmission signals from wireless transmissiondevice (not shown). Antenna 104 may operate, for example in the range of2.4 GHz with a bandwidth of 465 MHz. The received signals are thenprovided to If the transmission facility for example is a person with atransmission facility (wristband) may allow or prevent them fromaccessing an area, it may also alert the central unit of their enteringor desire to enter a restricted area. In an another embodiment, if thetransmission facility for example were a cell phone and the cell phonewas in use within a restricted area, the cell phone would be identifiedby the central unit as being in a restricted area, then the system willdetermine whether the cell phone is authorized or not authorized, thenthe system would make a determination, based upon set rules whether toallow or disallow the transmission unit.

The cell scan-2 detection system 1100, shown in FIG. 11, shows analternate embodiment of a system for detecting a signal of atransmission facility. For this embodiment the RF filters (i.e., bandpass filter) isolate sets of frequency for greater sensitivity, in thisexample a Low band cell phone signals and high band cell phone signals.The operation of the elements of FIG. 11 is similar to that of FIG. 10and need not be discussed in detail herein.

The main board system 1200, shown in FIG. 12, is an embodiment of a maincircuit board within a system for detecting transmission facilities. Thesystem may be used to determine each signal received is an actual cellphone signal and not a spurious output, a test may need to be performedthat checks for the ‘persistence’ of the received signal. A persistencetest may run a timer 1202 for a minimum required time that may be nearlyas long as the time of the shortest signal type expected. If the signalis present at the end of the timeout period, it is less likely to be aspurious response and more likely that it is a cell phone output. Forexample, if a GSM signal of 500 microseconds long is the shortestduration signal of all the cell phone protocols received, thepersistence test may run for 450 microseconds to further ensure that thereceived signal is not merely a spurious response.

The sub-station system 1300, shown in FIG. 13, is an embodiment of asub-station in a system for detecting transmission facilities.

FIG. 14 illustrates an embodiment of a null detector (1400), wherein theVCO in FIG. 14 tunes to known antenna frequencies and the system detectsa null in the known antenna frequencies in which the antenna isdetected. In embodiments, the null detection system may detect thepresence of a transmission facility even when the transmission facilityis not transmitting a signal. In embodiments, a hand held or mountednull detection device may be used in a correctional institution or othergovernment facility. In embodiments, null detection may utilize atransmission-detection source, independent of the transmission sourcebeing detected, which is capable of sweeping across the frequencyspectrum of interest and receiving it's returning signal. Thetransmission source sweeps the spectrum of interest, searching fordistortions in the returned field. Distortions in the spectrum may bedue to the presence of an antenna of a transmission facility 202.

In embodiments of the system described herein, detection levels may bedetermined by which output levels are possible with the various cellphone technologies that are in use today. Since the system described isan amplitude system, the strongest and weakest possible signals must bedetermined in order to identify the system's required dynamic range.Cell phone signals vary from −22 dBW to 6 DBW and this range defines thedetection requirements of the system. This translates to a maximumsignal of 4.0 Watts at the antenna. The minimum value is equal to 0.006Watts or 6 milliwatts. Therefore, the dynamic range required is −52 dBmto +36 dBm. In order to achieve such a dynamic range, an amplifier thatis gain adjustable is required such that an input value of +36 dBm, theamplifier is not saturated.

In the embodiment, the system determines the characteristics required toinsure that each cell phone is correctly identified. The amplitude ofeach signal is determined which allows the system to determine whichsensor has received the largest signal. The system time stamps each datasample so that other sensors receiving the same signal will berecognized as such when the data is presented for analysis. Each sensoranalyzes the wave shape of the signal detected. Each transmission type(i.e., CDMA2000, PCS, TDMA, GSM, IS-95, etc.) has a unique wave shape.These wave shapes allow the analysis software to recognize that signalsseen in different parts of a facility can be associated with each other(using time and wave shape) and the signal that consistently containsthe largest amplitude will be identified as closest to the cell phonetransmission

In embodiments of the invention, signals directed toward an IED(improvised explosive device) may be intercepted, identified and deniedservice. Such interception may be up to a known range in forward andside quadrants. The identification and determination of the position ofthe person or persons using a satellite phone and/or land-based cellphone may be determined. Cell phones, as well as other RF devices, e.g.,garage door openers, walkie-talkie, etc., may be captured, identifiedand/or jammed that are attempting to activate or contact the IED.

In embodiments of the invention, when a cell phone, for example, is on,but not in an active communication, the cell phone is essentiallyinvisible to anyone attempting to monitor cell phone activity. In orderto be aware of the existence of such “on but not transmitting devices”the system described herein operates as a cell tower. That is, thesystem actively addresses the problem of cell phone detection byoperating (becoming) the tower. A vehicle with similar (but modifiedequipment to that of a cell tower may actively poll the area of phonesthat are “on but not in a communication of any sort.” The vehicle (i.e.,Pseudo Tower) collects the current database of active phones and thosephones in standby from the tower(s) in the area and uses this data baseto poll these phones in order to locate them. Once potential phones thatcould be possible detonation cell phones are identified and located, thePseudo Tower would affect a handoff and make itself the active tower.Thus, the captured cell phones are not allowed to rotate back to (i.e.,connect to) the local cell phone tower, insuring that any callsattempting to communicate with the detonation cell phone will not besent. As one of the goals is to identify the person who is attempting tocontact the detonation cell phone, a call history of each suspect cellphone may be analyzed.

When a caller attempts to activate an IED, the caller's presence can beidentified. Furthermore, the call being made is not forwarded to thedetonation cell phone and the IED will not be activated. By determininga peak angle (triangulation) the caller's cell phone/satellite phonesignal, the direction of the caller is then known. Directionidentification is performed by using a technique such an interferometry.In this case, multiple antennas employing interferometry may be used toscan through the current cell phone traffic identifying first, candidatethreats and then, pinpointing high probability locations which can beviewed through a high powered binoculars to determine whether thecandidate is in need of investigation. Criteria for determining whichcell locations may be threats is a pole or road sign, etc. The PsuedoTower may continue controlling all of the phones in the area, preventingany forwarding of calls until all possible threats have been cleared. Atthis point, the personnel have the option of going after the caller ordeactivating the IED, or both. It would be possible to clear the areaand detonate the device later if that is a desired plan of action.

Given the varying parameters by which detonation can take place, thePseudo Tower may also be designed to deny service to any active andinactive phone within a given geographical area and pinpoint thelocation of said phones.

Satellite cell phone transmission presents a somewhat different problem.Since the transmission from phone to satellite to phone is communicatedto a number of satellites, becoming a replacement for the satellite willrequire cooperation from the provider. Via one or more specific codes,the satellites may be told that the vehicle mounted satellite simulator(i.e., Pseudo Tower) will be taking over the control of phones within acertain radius. Since this is a moving or ever changing circle, thereplacement “satellite” will have to continuously update the actualsatellite of its position and which phones are being released and whichphones are being controlled. Once this function has been implemented,the control of the suspect phones is similar to that of the cell phone.Determining the caller's position and the location of the detonationphone is as above.

Documents referenced herein are hereby incorporated in their entirety byreference. While the invention has been described in connection withcertain preferred embodiments, other embodiments would be understood byone of ordinary skill in the art and are encompassed herein.

1. A system for determining presence of a transmission facilitycomprising: a transmitting device for transmitting each of a pluralityof frequencies; a receiving device for receiving a return of eachtransmitted frequency produced by an antenna associated with thetransmission facility; a computer for: receiving the returnedtransmission frequencies from the receiving device; formulating adisturbance pattern from said returned transmission frequencies;comparing the disturbance pattern with a plurality of known disturbancepatterns; and determining a presence of the transmission facility basedon the comparison.
 2. The system of claim 1, wherein the plurality ofknown disturbance patterns are stored in a data base.
 3. The system ofclaim 1, the computer further: determining a null within saiddisturbance pattern.
 4. The system of claim 1, wherein the transmissionfacility is in at least one of: a powered-on state, a powered-off stateand a standby state.
 5. The system of claim 1, wherein the plurality offrequencies are transmitted from a first frequency to a secondfrequency.
 6. The system of claim 5, wherein the first and secondfrequencies represent edge frequencies of at least one known frequencyband.
 7. A null detector comprising; a receiving system; and aprocessor, said receiving system providing at least one frequency tosaid processor; said processor formulating a receiving pattern from saidat least one frequency and determining a disturbance is said receivingpattern, said disturbance representative of a presence of antransmission device.
 8. The null detector of claim 7, furthercomprising; a transmitting system for sequentially transmitting said atleast one frequency.
 9. The null detector of claim 7, furthercomprising: a data base for storing a plurality of disturbance patterns.10. The null detector of claim 9, the processor further: comparing saiddisturbance with said plurality of disturbance patterns; and identifyingsaid transmission device based on said comparison.